In modern painting systems, increased use is being made of applicator devices which employ a high-voltage electrode to ionise the paint being sprayed by them, so that it is drawn by electrostatic forces onto the objects to be coated, which are generally at the earth potential. In such painting systems, there is often a need for sensors which are at the same high electrical potential as the applicator device itself. An example of such a sensor is a detector which establishes whether a shuttle responsible for transporting the paint to the applicator device is present in the shuttle station next to the applicator device. These sensors, which in general operate electrically, require an electrical power supply. This, however, presents difficulties owing to the high potential of the sensors.
In known painting systems with electrical sensors which are at a high potential, the latter are supplied from batteries. These, however, have only a short service life so that the operation of the painting system has to be interrupted frequently in order to replace the batteries.